<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>perl5300delta - what is new for perl v5.30.0 - Perldoc Browser</title>
    <link rel="search" href="https://perldoc.perl.org/opensearch.xml" type="application/opensearchdescription+xml" title="Perldoc Browser">
    <link rel="canonical" href="https://perldoc.perl.org/perl5300delta">
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.5.0/styles/stackoverflow-light.min.css" integrity="sha512-cG1IdFxqipi3gqLmksLtuk13C+hBa57a6zpWxMeoY3Q9O6ooFxq50DayCdm0QrDgZjMUn23z/0PMZlgft7Yp5Q==" crossorigin="anonymous" />
    <style>
      body {
        background: #f4f4f5;
        color: #020202;
      }
      .navbar-dark {
        background-image: -webkit-linear-gradient(top, #005f85 0, #002e49 100%);
        background-image: -o-linear-gradient(top, #005f85 0, #002e49 100%);
        background-image: linear-gradient(to bottom, #005f85 0, #002e49 100%);
        filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff005f85', endColorstr='#ff002e49', GradientType=0);
        background-repeat: repeat-x;
      }
      .navbar-dark .navbar-nav .nav-link,
      .navbar-dark .navbar-nav .nav-link:focus { color: #fff }
      .navbar-dark .navbar-nav .nav-link:hover { color: #ffef68 }
      #wrapperlicious {
        margin: 0 auto;
        font: 0.9em 'Helvetica Neue', Helvetica, sans-serif;
        font-weight: normal;
        line-height: 1.5em;
        margin: 0;
        padding: 0;
      }
      #wrapperlicious h1 { font-size: 1.5em }
      #wrapperlicious h2 { font-size: 1.3em }
      #wrapperlicious h3 { font-size: 1.1em }
      #wrapperlicious h4 { font-size: 0.9em }
      #wrapperlicious h1, #wrapperlicious h2, #wrapperlicious h3,
      #wrapperlicious h4, #wrapperlicious dt {
        color: #020202;
        margin-top: 1em;
        margin-bottom: 1em;
        position: relative;
        font-weight: bold;
      }
      #wrapperlicious a { color: inherit; text-decoration: underline }
      #wrapperlicious #toc { text-decoration: none }
      #wrapperlicious a:hover { color: #2a2a2a }
      #wrapperlicious a img { border: 0 }
      #wrapperlicious :not(pre) > code {
        color: inherit;
        background-color: rgba(0, 0, 0, 0.04);
        border-radius: 3px;
        font: 0.9em Consolas, Menlo, Monaco, monospace;
        padding: 0.3em;
      }
      #wrapperlicious dd {
        margin: 0;
        margin-left: 2em;
      }
      #wrapperlicious dt {
        color: #2a2a2a;
        font-weight: bold;
        margin-left: 0.9em;
      }
      #wrapperlicious p {
        margin-bottom: 1em;
        margin-top: 1em;
      }
      #wrapperlicious li > p {
        margin-bottom: 0;
        margin-top: 0;
      }
      #wrapperlicious pre {
        border: 1px solid #c1c1c1;
        border-radius: 3px;
        font: 100% Consolas, Menlo, Monaco, monospace;
        margin-bottom: 1em;
        margin-top: 1em;
      }
      #wrapperlicious pre > code {
        display: block;
        background-color: #f6f6f6;
        font: 0.9em Consolas, Menlo, Monaco, monospace;
        line-height: 1.5em;
        text-align: left;
        white-space: pre;
        padding: 1em;
      }
      #wrapperlicious dl, #wrapperlicious ol, #wrapperlicious ul {
        margin-bottom: 1em;
        margin-top: 1em;
      }
      #wrapperlicious ul {
        list-style-type: square;
      }
      #wrapperlicious ul ul {
        margin-bottom: 0px;
        margin-top: 0px;
      }
      #footer {
        font-size: 0.8em;
        padding-top: 0.5em;
        text-align: center;
      }
      #more {
        display: inline;
        font-size: 0.8em;
      }
      #perldocdiv {
        background-color: #fff;
        border: 1px solid #c1c1c1;
        border-bottom-left-radius: 5px;
        border-bottom-right-radius: 5px;
        margin-left: auto;
        margin-right: auto;
        padding: 3em;
        padding-top: 1em;
        max-width: 960px;
      }
      #moduleversion { float: right }
      #wrapperlicious .leading-notice {
        font-style: italic;
        padding-left: 1em;
        margin-top: 1em;
        margin-bottom: 1em;
      }
      #wrapperlicious .permalink {
        display: none;
        left: -0.75em;
        position: absolute;
        padding-right: 0.25em;
        text-decoration: none;
      }
      #wrapperlicious h1:hover .permalink, #wrapperlicious h2:hover .permalink,
      #wrapperlicious h3:hover .permalink, #wrapperlicious h4:hover .permalink,
      #wrapperlicious dt:hover .permalink {
        display: block;
      }
    </style>
    <!-- Global site tag (gtag.js) - Google Analytics -->
    <script async src="https://www.googletagmanager.com/gtag/js?id=G-KVNWBNT5FB"></script>
    <script>
      window.dataLayer = window.dataLayer || [];
      function gtag(){dataLayer.push(arguments);}
      gtag('js', new Date());

      gtag('config', 'G-KVNWBNT5FB');
      gtag('config', 'UA-50555-3');
    </script>
  </head>
  <body>
    <nav class="navbar navbar-expand-md navbar-dark bg-dark justify-content-between">
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="https://perldoc.perl.org/">Perldoc Browser</a>
  <div class="collapse navbar-collapse" id="navbarNav">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item dropdown text-nowrap">
        <a class="nav-link dropdown-toggle" href="perl5300delta.html#" id="dropdownlink-stable" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">5.35.0</a>
        <div class="dropdown-menu" aria-labelledby="dropdownlink-stable">
          <a class="dropdown-item" href="https://perldoc.perl.org/perl5300delta">Latest</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.2/perl5300delta">5.38.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.1/perl5300delta">5.38.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.0/perl5300delta">5.38.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.3/perl5300delta">5.36.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.2/perl5300delta">5.36.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.1/perl5300delta">5.36.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.0/perl5300delta">5.36.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.3/perl5300delta">5.34.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.2/perl5300delta">5.34.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.1/perl5300delta">5.34.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.0/perl5300delta">5.34.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.32.1/perl5300delta">5.32.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.32.0/perl5300delta">5.32.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.3/perl5300delta">5.30.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.2/perl5300delta">5.30.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.1/perl5300delta">5.30.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.0/perl5300delta">5.30.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.3/perl5300delta">5.28.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.2/perl5300delta">5.28.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.1/perl5300delta">5.28.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.0/perl5300delta">5.28.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.3/perl5300delta">5.26.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.2/perl5300delta">5.26.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.1/perl5300delta">5.26.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.0/perl5300delta">5.26.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.4/perl5300delta">5.24.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.3/perl5300delta">5.24.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.2/perl5300delta">5.24.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.1/perl5300delta">5.24.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.0/perl5300delta">5.24.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.4/perl5300delta">5.22.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.3/perl5300delta">5.22.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.2/perl5300delta">5.22.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.1/perl5300delta">5.22.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.0/perl5300delta">5.22.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.3/perl5300delta">5.20.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.2/perl5300delta">5.20.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.1/perl5300delta">5.20.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.0/perl5300delta">5.20.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.4/perl5300delta">5.18.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.3/perl5300delta">5.18.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.2/perl5300delta">5.18.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.1/perl5300delta">5.18.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.0/perl5300delta">5.18.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.3/perl5300delta">5.16.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.2/perl5300delta">5.16.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.1/perl5300delta">5.16.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.0/perl5300delta">5.16.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.4/perl5300delta">5.14.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.3/perl5300delta">5.14.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.2/perl5300delta">5.14.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.1/perl5300delta">5.14.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.0/perl5300delta">5.14.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.5/perl5300delta">5.12.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.4/perl5300delta">5.12.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.3/perl5300delta">5.12.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.2/perl5300delta">5.12.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.1/perl5300delta">5.12.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.0/perl5300delta">5.12.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.10.1/perl5300delta">5.10.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.10.0/perl5300delta">5.10.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.9/perl5300delta">5.8.9</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.8/perl5300delta">5.8.8</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.7/perl5300delta">5.8.7</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.6/perl5300delta">5.8.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.5/perl5300delta">5.8.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.4/perl5300delta">5.8.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.3/perl5300delta">5.8.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.2/perl5300delta">5.8.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.1/perl5300delta">5.8.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.0/perl5300delta">5.8.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.6.2/perl5300delta">5.6.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.6.1/perl5300delta">5.6.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.6.0/perl5300delta">5.6.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_04/perl5300delta">5.005_04</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_03/perl5300delta">5.005_03</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_02/perl5300delta">5.005_02</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_01/perl5300delta">5.005_01</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005/perl5300delta">5.005</a>
        </div>
      </li>
      <li class="nav-item dropdown text-nowrap">
        <a class="nav-link dropdown-toggle" href="perl5300delta.html#" id="dropdownlink-dev" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dev</a>
        <div class="dropdown-menu" aria-labelledby="dropdownlink-dev">
          <a class="dropdown-item" href="https://perldoc.perl.org/blead/perl5300delta">blead</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.6/perl5300delta">5.39.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.5/perl5300delta">5.39.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.4/perl5300delta">5.39.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.3/perl5300delta">5.39.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.2/perl5300delta">5.39.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.1/perl5300delta">5.39.1</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.0-RC2/perl5300delta">5.38.0-RC2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.0-RC1/perl5300delta">5.38.0-RC1</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.11/perl5300delta">5.37.11</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.10/perl5300delta">5.37.10</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.9/perl5300delta">5.37.9</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.8/perl5300delta">5.37.8</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.7/perl5300delta">5.37.7</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.6/perl5300delta">5.37.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.5/perl5300delta">5.37.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.4/perl5300delta">5.37.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.3/perl5300delta">5.37.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.2/perl5300delta">5.37.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.1/perl5300delta">5.37.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.0/perl5300delta">5.37.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.11/perl5300delta">5.35.11</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.10/perl5300delta">5.35.10</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.9/perl5300delta">5.35.9</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.8/perl5300delta">5.35.8</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.7/perl5300delta">5.35.7</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.6/perl5300delta">5.35.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.5/perl5300delta">5.35.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.4/perl5300delta">5.35.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.3/perl5300delta">5.35.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.2/perl5300delta">5.35.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.1/perl5300delta">5.35.1</a>
          <a class="dropdown-item active" href="perl5300delta.html">5.35.0</a>
        </div>
      </li>
      <li class="nav-item dropdown text-nowrap">
        <a class="nav-link dropdown-toggle" href="perl5300delta.html#" id="dropdownlink-nav" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Documentation</a>
        <div class="dropdown-menu" aria-labelledby="dropdownlink-nav">
          <a class="dropdown-item" href="perl.html">Perl</a>
          <a class="dropdown-item" href="perlintro.html">Intro</a>
          <a class="dropdown-item" href="perl.html#Tutorials">Tutorials</a>
          <a class="dropdown-item" href="perlfaq.html">FAQs</a>
          <a class="dropdown-item" href="perl.html#Reference-Manual">Reference</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="perlop.html">Operators</a>
          <a class="dropdown-item" href="functions.html">Functions</a>
          <a class="dropdown-item" href="variables.html">Variables</a>
          <a class="dropdown-item" href="modules.html">Modules</a>
          <a class="dropdown-item" href="perlutil.html">Utilities</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="perlcommunity.html">Community</a>
          <a class="dropdown-item" href="perlhist.html">History</a>
        </div>
      </li>
    </ul>
    <ul class="navbar-nav">
      <script>
        function set_expand (expand) {
          var perldocdiv = document.getElementById('perldocdiv');
          var width = window.getComputedStyle(perldocdiv).getPropertyValue('max-width');
          var expanded = (width == '' || width == 'none') ? true : false;
          if (expand === null) {
            expand = !expanded;
          }
          if ((expand && !expanded) || (!expand && expanded)) {
            perldocdiv.style.setProperty('max-width', expand ? 'none' : '960px');
            var button_classlist = document.getElementById('content-expand-button').classList;
            if (expand) {
              button_classlist.add('btn-light');
              button_classlist.remove('btn-outline-light');
            } else {
              button_classlist.add('btn-outline-light');
              button_classlist.remove('btn-light');
            }
          }
          return expand;
        }
        function toggle_expand () {
          var expand = set_expand(null);
          document.cookie = 'perldoc_expand=' + (expand ? 1 : 0) + '; path=/; expires=Tue, 19 Jan 2038 03:14:07 UTC';
        }
        function read_expand () {
          return document.cookie.split(';').some(function (item) { return item.indexOf('perldoc_expand=1') >= 0 });
        }
        if (document.readyState === 'loading') {
          document.addEventListener('DOMContentLoaded', function () {
            if (read_expand()) {
              set_expand(true);
            }
          });
        } else if (read_expand()) {
          set_expand(true);
        }
      </script>
      <button id="content-expand-button" type="button" class="btn btn-outline-light d-none d-lg-inline-block mr-2" onclick="toggle_expand()">Expand</button>
    <ul>
    <form class="form-inline" method="get" action="https://perldoc.perl.org/5.35.0/search">
      <input class="form-control mr-3" type="search" name="q" placeholder="Search" aria-label="Search">
    </form>
  </div>
</nav>

    <div id="wrapperlicious" class="container-fluid">
      <div id="perldocdiv">
        <div id="links">
          <a href="perl5300delta.html">perl5300delta</a>
          <div id="more">
            (<a href="perl5300delta.txt">source</a>,
            <a href="https://metacpan.org/pod/perl5300delta">CPAN</a>)
          </div>
        </div>
        <div class="leading-notice">
          You are viewing the version of this documentation from Perl 5.35.0.
            This is a development version of Perl.
        </div>
        <h1><a id="toc">CONTENTS</a></h1>
                  <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#NAME">NAME</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#DESCRIPTION">DESCRIPTION</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Notice">Notice</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Core-Enhancements">Core Enhancements</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Limited-variable-length-lookbehind-in-regular-expression-pattern-matching-is-now-experimentally-supported">Limited variable length lookbehind in regular expression pattern matching is now experimentally supported</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#The-upper-limit-%22n%22-specifiable-in-a-regular-expression-quantifier-of-the-form-%22%7Bm,n%7D%22-has-been-doubled-to-65534">The upper limit &quot;n&quot; specifiable in a regular expression quantifier of the form &quot;{m,n}&quot; has been doubled to 65534</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Unicode-12.1-is-supported">Unicode 12.1 is supported</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Wildcards-in-Unicode-property-value-specifications-are-now-partially-supported">Wildcards in Unicode property value specifications are now partially supported</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#qr&#39;%5CN%7Bname%7D&#39;-is-now-supported">qr&#39;\N{name}&#39; is now supported</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Turkic-UTF-8-locales-are-now-seamlessly-supported">Turkic UTF-8 locales are now seamlessly supported</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#It-is-now-possible-to-compile-perl-to-always-use-thread-safe-locale-operations.">It is now possible to compile perl to always use thread-safe locale operations.</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Eliminate-opASSIGN-macro-usage-from-core">Eliminate opASSIGN macro usage from core</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#-Drv-now-means-something-on-DDEBUGGING-builds">-Drv now means something on -DDEBUGGING builds</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Incompatible-Changes">Incompatible Changes</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Assigning-non-zero-to-$%5B-is-fatal">Assigning non-zero to $[ is fatal</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Delimiters-must-now-be-graphemes">Delimiters must now be graphemes</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Some-formerly-deprecated-uses-of-an-unescaped-left-brace-%22%7B%22-in-regular-expression-patterns-are-now-illegal">Some formerly deprecated uses of an unescaped left brace &quot;{&quot; in regular expression patterns are now illegal</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Previously-deprecated-sysread()/syswrite()-on-:utf8-handles-is-now-fatal">Previously deprecated sysread()/syswrite() on :utf8 handles is now fatal</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#my()-in-false-conditional-prohibited">my() in false conditional prohibited</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Fatalize-$*-and-$%23">Fatalize $* and $#</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Fatalize-unqualified-use-of-dump()">Fatalize unqualified use of dump()</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Remove-File::Glob::glob()">Remove File::Glob::glob()</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#pack()-no-longer-can-return-malformed-UTF-8">pack() no longer can return malformed UTF-8</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Any-set-of-digits-in-the-Common-script-are-legal-in-a-script-run-of-another-script">Any set of digits in the Common script are legal in a script run of another script</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#JSON::PP-enables-allow_nonref-by-default">JSON::PP enables allow_nonref by default</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Deprecations">Deprecations</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#In-XS-code,-use-of-various-macros-dealing-with-UTF-8.">In XS code, use of various macros dealing with UTF-8.</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Performance-Enhancements">Performance Enhancements</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Modules-and-Pragmata">Modules and Pragmata</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Updated-Modules-and-Pragmata">Updated Modules and Pragmata</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Removed-Modules-and-Pragmata">Removed Modules and Pragmata</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Documentation">Documentation</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Changes-to-Existing-Documentation">Changes to Existing Documentation</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlapi">perlapi</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlop">perlop</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlreapi,-perlvar">perlreapi, perlvar</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlfunc">perlfunc</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlreref">perlreref</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perllocale">perllocale</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlrecharclass">perlrecharclass</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#perlvar">perlvar</a>
              </li>
          </ul>

              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Diagnostics">Diagnostics</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Changes-to-Existing-Diagnostics">Changes to Existing Diagnostics</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Utility-Changes">Utility Changes</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#xsubpp">xsubpp</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Configuration-and-Compilation">Configuration and Compilation</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Testing">Testing</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Platform-Support">Platform Support</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Platform-Specific-Notes">Platform-Specific Notes</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Internal-Changes">Internal Changes</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Selected-Bug-Fixes">Selected Bug Fixes</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Acknowledgements">Acknowledgements</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Reporting-Bugs">Reporting Bugs</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#Give-Thanks">Give Thanks</a>
              </li>
              <li>
                <a class="text-decoration-none" href="perl5300delta.html#SEE-ALSO">SEE ALSO</a>
              </li>
          </ul>

      <h1 id="NAME"><a class="permalink" href="perl5300delta.html#NAME">#</a>NAME</h1>

<p>perl5300delta - what is new for perl v5.30.0</p>

<h1 id="DESCRIPTION"><a class="permalink" href="perl5300delta.html#DESCRIPTION">#</a>DESCRIPTION</h1>

<p>This document describes differences between the 5.28.0 release and the 5.30.0 release.</p>

<p>If you are upgrading from an earlier release such as 5.26.0, first read <a href="perl5280delta.html">perl5280delta</a>, which describes differences between 5.26.0 and 5.28.0.</p>

<h1 id="Notice"><a class="permalink" href="perl5300delta.html#Notice">#</a>Notice</h1>

<p>sv_utf8_(downgrade|decode) are no longer marked as experimental. <a href="https://github.com/Perl/perl5/issues/16822">[GH #16822]</a>.</p>

<h1 id="Core-Enhancements"><a class="permalink" href="perl5300delta.html#Core-Enhancements">#</a><a id="Core"></a>Core Enhancements</h1>

<h2 id="Limited-variable-length-lookbehind-in-regular-expression-pattern-matching-is-now-experimentally-supported"><a class="permalink" href="perl5300delta.html#Limited-variable-length-lookbehind-in-regular-expression-pattern-matching-is-now-experimentally-supported">#</a><a id="Limited"></a>Limited variable length lookbehind in regular expression pattern matching is now experimentally supported</h2>

<p>Using a lookbehind assertion (like <code>(?&lt;=foo?)</code> or <code>(?&lt;!ba{1,9}r)</code> previously would generate an error and refuse to compile. Now it compiles (if the maximum lookbehind is at most 255 characters), but raises a warning in the new <code>experimental::vlb</code> warnings category. This is to caution you that the precise behavior is subject to change based on feedback from use in the field.</p>

<p>See <a href="perlre.html#%28%3F%3C%3Dpattern%29">&quot;(?&lt;=pattern)&quot; in perlre</a> and <a href="perlre.html#%28%3F%3C%21pattern%29">&quot;(?&lt;!pattern)&quot; in perlre</a>.</p>

<h2 id="The-upper-limit-&quot;n&quot;-specifiable-in-a-regular-expression-quantifier-of-the-form-&quot;{m,n}&quot;-has-been-doubled-to-65534"><a class="permalink" href="perl5300delta.html#The-upper-limit-%22n%22-specifiable-in-a-regular-expression-quantifier-of-the-form-%22%7Bm,n%7D%22-has-been-doubled-to-65534">#</a><a id="The"></a><a id="The-upper-limit-n-specifiable-in-a-regular-expression-quantifier-of-the-form-m-n-has-been-doubled-to-65534"></a>The upper limit <code>&quot;n&quot;</code> specifiable in a regular expression quantifier of the form <code>&quot;{m,n}&quot;</code> has been doubled to 65534</h2>

<p>The meaning of an unbounded upper quantifier <code>&quot;{m,}&quot;</code> remains unchanged. It matches 2**31 - 1 times on most platforms, and more on ones where a C language short variable is more than 4 bytes long.</p>

<h2 id="Unicode-12.1-is-supported"><a class="permalink" href="perl5300delta.html#Unicode-12.1-is-supported">#</a><a id="Unicode"></a>Unicode 12.1 is supported</h2>

<p>Because of a change in Unicode release cycles, Perl jumps from Unicode 10.0 in Perl 5.28 to Unicode 12.1 in Perl 5.30.</p>

<p>For details on the Unicode changes, see <a href="https://www.unicode.org/versions/Unicode11.0.0/">https://www.unicode.org/versions/Unicode11.0.0/</a> for 11.0; <a href="https://www.unicode.org/versions/Unicode12.0.0/">https://www.unicode.org/versions/Unicode12.0.0/</a> for 12.0; and <a href="https://www.unicode.org/versions/Unicode12.1.0/">https://www.unicode.org/versions/Unicode12.1.0/</a> for 12.1. (Unicode 12.1 differs from 12.0 only in the addition of a single character, that for the new Japanese era name.)</p>

<p>The Word_Break property, as in past Perl releases, remains tailored to behave more in line with expectations of Perl users. This means that sequential runs of horizontal white space characters are not broken apart, but kept as a single run. Unicode 11 changed from past versions to be more in line with Perl, but it left several white space characters as causing breaks: TAB, NO BREAK SPACE, and FIGURE SPACE (U+2007). We have decided to continue to use the previous Perl tailoring with regards to these.</p>

<h2 id="Wildcards-in-Unicode-property-value-specifications-are-now-partially-supported"><a class="permalink" href="perl5300delta.html#Wildcards-in-Unicode-property-value-specifications-are-now-partially-supported">#</a><a id="Wildcards"></a>Wildcards in Unicode property value specifications are now partially supported</h2>

<p>You can now do something like this in a regular expression pattern</p>

<pre><code class="plaintext">qr! \p{nv= /(?x) \A [0-5] \z / }!</code></pre>

<p>which matches all Unicode code points whose numeric value is between 0 and 5 inclusive. So, it could match the Thai or Bengali digits whose numeric values are 0, 1, 2, 3, 4, or 5.</p>

<p>This marks another step in implementing the regular expression features the Unicode Consortium suggests.</p>

<p>Most properties are supported, with the remainder planned for 5.32. Details are in <a href="perlunicode.html#Wildcards-in-Property-Values">&quot;Wildcards in Property Values&quot; in perlunicode</a>.</p>

<h2 id="qr&#39;\N{name}&#39;-is-now-supported"><a class="permalink" href="perl5300delta.html#qr&#39;%5CN%7Bname%7D&#39;-is-now-supported">#</a><a id="qr"></a><a id="qr-N-name-is-now-supported"></a>qr&#39;\N{name}&#39; is now supported</h2>

<p>Previously it was an error to evaluate a named character <code>\N{...}</code> within a single quoted regular expression pattern (whose evaluation is deferred from the normal place). This restriction is now removed.</p>

<h2 id="Turkic-UTF-8-locales-are-now-seamlessly-supported"><a class="permalink" href="perl5300delta.html#Turkic-UTF-8-locales-are-now-seamlessly-supported">#</a><a id="Turkic"></a>Turkic UTF-8 locales are now seamlessly supported</h2>

<p>Turkic languages have different casing rules than other languages for the characters <code>&quot;i&quot;</code> and <code>&quot;I&quot;</code>. The uppercase of <code>&quot;i&quot;</code> is LATIN CAPITAL LETTER I WITH DOT ABOVE (U+0130); and the lowercase of <code>&quot;I&quot;</code> is LATIN SMALL LETTER DOTLESS I (U+0131). Unicode furnishes alternate casing rules for use with Turkic languages. Previously, Perl ignored these, but now, it uses them when it detects that it is operating under a Turkic UTF-8 locale.</p>

<h2 id="It-is-now-possible-to-compile-perl-to-always-use-thread-safe-locale-operations."><a class="permalink" href="perl5300delta.html#It-is-now-possible-to-compile-perl-to-always-use-thread-safe-locale-operations.">#</a><a id="It"></a><a id="It-is-now-possible-to-compile-perl-to-always-use-thread-safe-locale-operations"></a>It is now possible to compile perl to always use thread-safe locale operations.</h2>

<p>Previously, these calls were only used when the perl was compiled to be multi-threaded. To always enable them, add</p>

<pre><code class="plaintext">-Accflags=&#39;-DUSE_THREAD_SAFE_LOCALE&#39;</code></pre>

<p>to your <i>Configure</i> flags.</p>

<h2 id="Eliminate-opASSIGN-macro-usage-from-core"><a class="permalink" href="perl5300delta.html#Eliminate-opASSIGN-macro-usage-from-core">#</a><a id="Eliminate"></a>Eliminate opASSIGN macro usage from core</h2>

<p>This macro is still defined but no longer used in core</p>

<h2 id="-Drv-now-means-something-on-DDEBUGGING-builds"><a class="permalink" href="perl5300delta.html#-Drv-now-means-something-on-DDEBUGGING-builds">#</a><a id="Drv-now-means-something-on--DDEBUGGING-builds"></a><code>-Drv</code> now means something on <code>-DDEBUGGING</code> builds</h2>

<p>Now, adding the verbose flag (<code>-Dv</code>) to the <code>-Dr</code> flag turns on all possible regular expression debugging.</p>

<h1 id="Incompatible-Changes"><a class="permalink" href="perl5300delta.html#Incompatible-Changes">#</a><a id="Incompatible"></a>Incompatible Changes</h1>

<h2 id="Assigning-non-zero-to-$[-is-fatal"><a class="permalink" href="perl5300delta.html#Assigning-non-zero-to-$%5B-is-fatal">#</a><a id="Assigning"></a><a id="Assigning-non-zero-to-is-fatal"></a>Assigning non-zero to <code>$[</code> is fatal</h2>

<p>Setting <a href="perlvar.html#%24%5B"><code>$[</code></a> to a non-zero value has been deprecated since Perl 5.12 and now throws a fatal error. See <a href="perldeprecation.html#Assigning-non-zero-to-%24%5B-is-fatal">&quot;Assigning non-zero to <code>$[</code> is fatal&quot; in perldeprecation</a>.</p>

<h2 id="Delimiters-must-now-be-graphemes"><a class="permalink" href="perl5300delta.html#Delimiters-must-now-be-graphemes">#</a><a id="Delimiters"></a>Delimiters must now be graphemes</h2>

<p>See <a href="perldeprecation.html#Use-of-unassigned-code-point-or-non-standalone-grapheme-for-a-delimiter.">&quot;Use of unassigned code point or non-standalone grapheme for a delimiter.&quot; in perldeprecation</a></p>

<h2 id="Some-formerly-deprecated-uses-of-an-unescaped-left-brace-&quot;{&quot;-in-regular-expression-patterns-are-now-illegal"><a class="permalink" href="perl5300delta.html#Some-formerly-deprecated-uses-of-an-unescaped-left-brace-%22%7B%22-in-regular-expression-patterns-are-now-illegal">#</a><a id="Some"></a><a id="Some-formerly-deprecated-uses-of-an-unescaped-left-brace-in-regular-expression-patterns-are-now-illegal"></a>Some formerly deprecated uses of an unescaped left brace <code>&quot;{&quot;</code> in regular expression patterns are now illegal</h2>

<p>But to avoid breaking code unnecessarily, most instances that issued a deprecation warning, remain legal and now have a non-deprecation warning raised. See <a href="perldeprecation.html#Unescaped-left-braces-in-regular-expressions">&quot;Unescaped left braces in regular expressions&quot; in perldeprecation</a>.</p>

<h2 id="Previously-deprecated-sysread()/syswrite()-on-:utf8-handles-is-now-fatal"><a class="permalink" href="perl5300delta.html#Previously-deprecated-sysread()/syswrite()-on-:utf8-handles-is-now-fatal">#</a><a id="Previously"></a><a id="Previously-deprecated-sysread-syswrite-on-:utf8-handles-is-now-fatal"></a>Previously deprecated sysread()/syswrite() on :utf8 handles is now fatal</h2>

<p>Calling sysread(), syswrite(), send() or recv() on a <code>:utf8</code> handle, whether applied explicitly or implicitly, is now fatal. This was deprecated in perl 5.24.</p>

<p>There were two problems with calling these functions on <code>:utf8</code> handles:</p>

<ul>

<li><p>All four functions only paid attention to the <code>:utf8</code> flag. Other layers were completely ignored, so a handle with <code>:encoding(UTF-16LE)</code> layer would be treated as UTF-8. Other layers, such as compression are completely ignored with or without the <code>:utf8</code> flag.</p>

</li>
<li><p>sysread() and recv() would read from the handle, skipping any validation by the layers, and do no validation of their own. This could lead to invalidly encoded perl scalars.</p>

</li>
</ul>

<p><a href="https://github.com/Perl/perl5/issues/14839">[GH #14839]</a>.</p>

<h2 id="my()-in-false-conditional-prohibited"><a class="permalink" href="perl5300delta.html#my()-in-false-conditional-prohibited">#</a><a id="my"></a><a id="my-in-false-conditional-prohibited"></a>my() in false conditional prohibited</h2>

<p>Declarations such as <code>my $x if 0</code> are no longer permitted.</p>

<p><a href="https://github.com/Perl/perl5/issues/16702">[GH #16702]</a>.</p>

<h2 id="Fatalize-$*-and-$#"><a class="permalink" href="perl5300delta.html#Fatalize-$*-and-$%23">#</a><a id="Fatalize"></a><a id="Fatalize-and"></a>Fatalize $* and $#</h2>

<p>These special variables, long deprecated, now throw exceptions when used.</p>

<p><a href="https://github.com/Perl/perl5/issues/16718">[GH #16718]</a>.</p>

<h2 id="Fatalize-unqualified-use-of-dump()"><a class="permalink" href="perl5300delta.html#Fatalize-unqualified-use-of-dump()">#</a><a id="Fatalize1"></a><a id="Fatalize-unqualified-use-of-dump"></a>Fatalize unqualified use of dump()</h2>

<p>The <code>dump()</code> function, long discouraged, may no longer be used unless it is fully qualified, <i>i.e.</i>, <code>CORE::dump()</code>.</p>

<p><a href="https://github.com/Perl/perl5/issues/16719">[GH #16719]</a>.</p>

<h2 id="Remove-File::Glob::glob()"><a class="permalink" href="perl5300delta.html#Remove-File::Glob::glob()">#</a><a id="Remove"></a><a id="Remove-File::Glob::glob"></a>Remove File::Glob::glob()</h2>

<p>The <code>File::Glob::glob()</code> function, long deprecated, has been removed and now throws an exception which advises use of <code>File::Glob::bsd_glob()</code> instead.</p>

<p><a href="https://github.com/Perl/perl5/issues/16721">[GH #16721]</a>.</p>

<h2 id="pack()-no-longer-can-return-malformed-UTF-8"><a class="permalink" href="perl5300delta.html#pack()-no-longer-can-return-malformed-UTF-8">#</a><a id="pack"></a><a id="pack-no-longer-can-return-malformed-UTF-8"></a><code>pack()</code> no longer can return malformed UTF-8</h2>

<p>It croaks if it would otherwise return a UTF-8 string that contains malformed UTF-8. This protects against potential security threats. This is considered a bug fix as well. <a href="https://github.com/Perl/perl5/issues/16035">[GH #16035]</a>.</p>

<h2 id="Any-set-of-digits-in-the-Common-script-are-legal-in-a-script-run-of-another-script"><a class="permalink" href="perl5300delta.html#Any-set-of-digits-in-the-Common-script-are-legal-in-a-script-run-of-another-script">#</a><a id="Any"></a>Any set of digits in the Common script are legal in a script run of another script</h2>

<p>There are several sets of digits in the Common script. <code>[0-9]</code> is the most familiar. But there are also <code>[\x{FF10}-\x{FF19}]</code> (FULLWIDTH DIGIT ZERO - FULLWIDTH DIGIT NINE), and several sets for use in mathematical notation, such as the MATHEMATICAL DOUBLE-STRUCK DIGITs. Any of these sets should be able to appear in script runs of, say, Greek. But the design of 5.30 overlooked all but the ASCII digits <code>[0-9]</code>, so the design was flawed. This has been fixed, so is both a bug fix and an incompatibility. <a href="https://github.com/Perl/perl5/issues/16704">[GH #16704]</a>.</p>

<p>All digits in a run still have to come from the same set of ten digits.</p>

<h2 id="JSON::PP-enables-allow_nonref-by-default"><a class="permalink" href="perl5300delta.html#JSON::PP-enables-allow_nonref-by-default">#</a><a id="JSON"></a>JSON::PP enables allow_nonref by default</h2>

<p>As JSON::XS 4.0 changed its policy and enabled allow_nonref by default, JSON::PP also enabled allow_nonref by default.</p>

<h1 id="Deprecations"><a class="permalink" href="perl5300delta.html#Deprecations">#</a>Deprecations</h1>

<h2 id="In-XS-code,-use-of-various-macros-dealing-with-UTF-8."><a class="permalink" href="perl5300delta.html#In-XS-code,-use-of-various-macros-dealing-with-UTF-8.">#</a><a id="In"></a><a id="In-XS-code-use-of-various-macros-dealing-with-UTF-8"></a>In XS code, use of various macros dealing with UTF-8.</h2>

<p>This deprecation was scheduled to become fatal in 5.30, but has been delayed to 5.32 due to problems that showed up with some CPAN modules. For details of what&#39;s affected, see <a href="https://perldoc.perl.org/5.35.0/&#32;perldeprecation#In-XS-code%2C-use-of-various-macros-dealing-with-UTF-8.">perldeprecation</a>.</p>

<h1 id="Performance-Enhancements"><a class="permalink" href="perl5300delta.html#Performance-Enhancements">#</a><a id="Performance"></a>Performance Enhancements</h1>

<ul>

<li><p>Translating from UTF-8 into the code point it represents now is done via a deterministic finite automaton, speeding it up. As a typical example, <code>ord(&quot;\x7fff&quot;)</code> now requires 12% fewer instructions than before. The performance of checking that a sequence of bytes is valid UTF-8 is similarly improved, again by using a DFA.</p>

</li>
<li><p>Eliminate recursion from finalize_op(). <a href="https://github.com/Perl/perl5/issues/11866">[GH #11866]</a>.</p>

</li>
<li><p>A handful of small optimizations related to character folding and character classes in regular expressions.</p>

</li>
<li><p>Optimization of <code>IV</code> to <code>UV</code> conversions. <a href="https://github.com/Perl/perl5/issues/16761">[GH #16761]</a>.</p>

</li>
<li><p>Speed up of the integer stringification algorithm by processing two digits at a time instead of one. <a href="https://github.com/Perl/perl5/issues/16769">[GH #16769]</a>.</p>

</li>
<li><p>Improvements based on LGTM analysis and recommendation. (<a href="https://lgtm.com/projects/g/Perl/perl5/alerts/?mode=tree">https://lgtm.com/projects/g/Perl/perl5/alerts/?mode=tree</a>). <a href="https://github.com/Perl/perl5/issues/16765">[GH #16765]</a>. <a href="https://github.com/Perl/perl5/issues/16773">[GH #16773]</a>.</p>

</li>
<li><p>Code optimizations in <i>regcomp.c</i>, <i>regcomp.h</i>, <i>regexec.c</i>.</p>

</li>
<li><p>Regular expression pattern matching of things like <code>qr/[^<i>a</i>]/</code> is significantly sped up, where <i>a</i> is any ASCII character. Other classes can get this speed up, but which ones is complicated and depends on the underlying bit patterns of those characters, so differs between ASCII and EBCDIC platforms, but all case pairs, like <code>qr/[Gg]/</code> are included, as is <code>[^01]</code>.</p>

</li>
</ul>

<h1 id="Modules-and-Pragmata"><a class="permalink" href="perl5300delta.html#Modules-and-Pragmata">#</a><a id="Modules"></a>Modules and Pragmata</h1>

<h2 id="Updated-Modules-and-Pragmata"><a class="permalink" href="perl5300delta.html#Updated-Modules-and-Pragmata">#</a><a id="Updated"></a>Updated Modules and Pragmata</h2>

<ul>

<li><p><a href="./Archive::Tar.html">Archive::Tar</a> has been upgraded from version 2.30 to 2.32.</p>

</li>
<li><p><a href="B.html">B</a> has been upgraded from version 1.74 to 1.76.</p>

</li>
<li><p><a href="./B::Concise.html">B::Concise</a> has been upgraded from version 1.003 to 1.004.</p>

</li>
<li><p><a href="./B::Deparse.html">B::Deparse</a> has been upgraded from version 1.48 to 1.49.</p>

</li>
<li><p><a href="bignum.html">bignum</a> has been upgraded from version 0.49 to 0.51.</p>

</li>
<li><p><a href="bytes.html">bytes</a> has been upgraded from version 1.06 to 1.07.</p>

</li>
<li><p><a href="Carp.html">Carp</a> has been upgraded from version 1.38 to 1.50</p>

</li>
<li><p><a href="./Compress::Raw::Bzip2.html">Compress::Raw::Bzip2</a> has been upgraded from version 2.074 to 2.084.</p>

</li>
<li><p><a href="./Compress::Raw::Zlib.html">Compress::Raw::Zlib</a> has been upgraded from version 2.076 to 2.084.</p>

</li>
<li><p><a href="./Config::Extensions.html">Config::Extensions</a> has been upgraded from version 0.02 to 0.03.</p>

</li>
<li><p><a href="./Config::Perl::V.html">Config::Perl::V</a>. has been upgraded from version 0.29 to 0.32. This was due to a new configuration variable that has influence on binary compatibility: <code>USE_THREAD_SAFE_LOCALE</code>.</p>

</li>
<li><p><a href="CPAN.html">CPAN</a> has been upgraded from version 2.20 to 2.22.</p>

</li>
<li><p><a href="./Data::Dumper.html">Data::Dumper</a> has been upgraded from version 2.170 to 2.174</p>

<p><a href="./Data::Dumper.html">Data::Dumper</a> now avoids leaking when <code>croak</code>ing.</p>

</li>
<li><p><a href="DB_File.html">DB_File</a> has been upgraded from version 1.840 to 1.843.</p>

</li>
<li><p><a href="deprecate.html">deprecate</a> has been upgraded from version 0.03 to 0.04.</p>

</li>
<li><p><a href="./Devel::Peek.html">Devel::Peek</a> has been upgraded from version 1.27 to 1.28.</p>

</li>
<li><p><a href="./Devel::PPPort.html">Devel::PPPort</a> has been upgraded from version 3.40 to 3.52.</p>

</li>
<li><p><a href="./Digest::SHA.html">Digest::SHA</a> has been upgraded from version 6.01 to 6.02.</p>

</li>
<li><p><a href="Encode.html">Encode</a> has been upgraded from version 2.97 to 3.01.</p>

</li>
<li><p><a href="Errno.html">Errno</a> has been upgraded from version 1.29 to 1.30.</p>

</li>
<li><p><a href="experimental.html">experimental</a> has been upgraded from version 0.019 to 0.020.</p>

</li>
<li><p><a href="./ExtUtils::CBuilder.html">ExtUtils::CBuilder</a> has been upgraded from version 0.280230 to 0.280231.</p>

</li>
<li><p><a href="./ExtUtils::Manifest.html">ExtUtils::Manifest</a> has been upgraded from version 1.70 to 1.72.</p>

</li>
<li><p><a href="./ExtUtils::Miniperl.html">ExtUtils::Miniperl</a> has been upgraded from version 1.08 to 1.09.</p>

</li>
<li><p><a href="./ExtUtils::ParseXS.html">ExtUtils::ParseXS</a> has been upgraded from version 3.39 to 3.40. <code>OUTLIST</code> parameters are no longer incorrectly included in the automatically generated function prototype. <a href="https://github.com/Perl/perl5/issues/16746">[GH #16746]</a>.</p>

</li>
<li><p><a href="feature.html">feature</a> has been upgraded from version 1.52 to 1.54.</p>

</li>
<li><p><a href="./File::Copy.html">File::Copy</a> has been upgraded from version 2.33 to 2.34.</p>

</li>
<li><p><a href="./File::Find.html">File::Find</a> has been upgraded from version 1.34 to 1.36.</p>

<p><code>$File::Find::dont_use_nlink</code> now defaults to 1 on all platforms. <a href="https://github.com/Perl/perl5/issues/16759">[GH #16759]</a>.</p>

<p>Variables <code>$Is_Win32</code> and <code>$Is_VMS</code> are being initialized.</p>

</li>
<li><p><a href="./File::Glob.html">File::Glob</a> has been upgraded from version 1.31 to 1.32.</p>

</li>
<li><p><a href="./File::Path.html">File::Path</a> has been upgraded from version 2.15 to 2.16.</p>

</li>
<li><p><a href="./File::Spec.html">File::Spec</a> has been upgraded from version 3.74 to 3.78.</p>

<p>Silence <a href="Cwd.html">Cwd</a> warning on Android builds if <code>targetsh</code> is not defined.</p>

</li>
<li><p><a href="./File::Temp.html">File::Temp</a> has been upgraded from version 0.2304 to 0.2309.</p>

</li>
<li><p><a href="./Filter::Util::Call.html">Filter::Util::Call</a> has been upgraded from version 1.58 to 1.59.</p>

</li>
<li><p><a href="GDBM_File.html">GDBM_File</a> has been upgraded from version 1.17 to 1.18.</p>

</li>
<li><p><a href="./HTTP::Tiny.html">HTTP::Tiny</a> has been upgraded from version 0.070 to 0.076.</p>

</li>
<li><p><a href="./I18N::Langinfo.html">I18N::Langinfo</a> has been upgraded from version 0.17 to 0.18.</p>

</li>
<li><p><a href="IO.html">IO</a> has been upgraded from version 1.39 to 1.40.</p>

</li>
<li><p>IO-Compress has been upgraded from version 2.074 to 2.084.</p>

<p>Adds support for <code>IO::Uncompress::Zstd</code> and <code>IO::Uncompress::UnLzip</code>.</p>

<p>The <code>BinModeIn</code> and <code>BinModeOut</code> options are now no-ops. ALL files will be read/written in binmode.</p>

</li>
<li><p><a href="./IPC::Cmd.html">IPC::Cmd</a> has been upgraded from version 1.00 to 1.02.</p>

</li>
<li><p><a href="./JSON::PP.html">JSON::PP</a> has been upgraded from version 2.97001 to 4.02.</p>

<p><a href="./JSON::PP.html">JSON::PP</a> as JSON::XS 4.0 enables <code>allow_nonref</code> by default.</p>

</li>
<li><p><a href="lib.html">lib</a> has been upgraded from version 0.64 to 0.65.</p>

</li>
<li><p><a href="./Locale::Codes.html">Locale::Codes</a> has been upgraded from version 3.56 to 3.57.</p>

</li>
<li><p><a href="./Math::BigInt.html">Math::BigInt</a> has been upgraded from version 1.999811 to 1.999816.</p>

<p><code>bnok()</code> now supports the full Kronenburg extension. <a href="https://rt.cpan.org/Ticket/Display.html?id=95628">[cpan #95628]</a>.</p>

</li>
<li><p><a href="./Math::BigInt::FastCalc.html">Math::BigInt::FastCalc</a> has been upgraded from version 0.5006 to 0.5008.</p>

</li>
<li><p><a href="./Math::BigRat.html">Math::BigRat</a> has been upgraded from version 0.2613 to 0.2614.</p>

</li>
<li><p><a href="./Module::CoreList.html">Module::CoreList</a> has been upgraded from version 5.20180622 to 5.20190520.</p>

<p>Changes to B::Op_private and Config</p>

</li>
<li><p><a href="./Module::Load.html">Module::Load</a> has been upgraded from version 0.32 to 0.34.</p>

</li>
<li><p><a href="./Module::Metadata.html">Module::Metadata</a> has been upgraded from version 1.000033 to 1.000036.</p>

<p>Properly clean up temporary directories after testing.</p>

</li>
<li><p><a href="NDBM_File.html">NDBM_File</a> has been upgraded from version 1.14 to 1.15.</p>

</li>
<li><p><a href="./Net::Ping.html">Net::Ping</a> has been upgraded from version 2.62 to 2.71.</p>

</li>
<li><p><a href="ODBM_File.html">ODBM_File</a> has been upgraded from version 1.15 to 1.16.</p>

</li>
<li><p>PathTools has been upgraded from version 3.74 to 3.78.</p>

</li>
<li><p><a href="parent.html">parent</a> has been upgraded from version 0.236 to 0.237.</p>

</li>
<li><p><a href="perl5db.pl">perl5db.pl</a> has been upgraded from version 1.54 to 1.55.</p>

<p>Debugging threaded code no longer deadlocks in <code>DB::sub</code> nor <code>DB::lsub</code>.</p>

</li>
<li><p><a href="perlfaq.html">perlfaq</a> has been upgraded from version 5.021011 to 5.20190126.</p>

</li>
<li><p><a href="./PerlIO::encoding.html">PerlIO::encoding</a> has been upgraded from version 0.26 to 0.27.</p>

<p>Warnings enabled by setting the <code>WARN_ON_ERR</code> flag in <code>$PerlIO::encoding::fallback</code> are now only produced if warnings are enabled with <code>use warnings &quot;utf8&quot;;</code> or setting <code>$^W</code>.</p>

</li>
<li><p><a href="./PerlIO::scalar.html">PerlIO::scalar</a> has been upgraded from version 0.29 to 0.30.</p>

</li>
<li><p>podlators has been upgraded from version 4.10 to 4.11.</p>

</li>
<li><p><a href="POSIX.html">POSIX</a> has been upgraded from version 1.84 to 1.88.</p>

</li>
<li><p><a href="re.html">re</a> has been upgraded from version 0.36 to 0.37.</p>

</li>
<li><p><a href="SDBM_File.html">SDBM_File</a> has been upgraded from version 1.14 to 1.15.</p>

</li>
<li><p><a href="sigtrap.html">sigtrap</a> has been upgraded from version 1.08 to 1.09.</p>

</li>
<li><p><a href="Storable.html">Storable</a> has been upgraded from version 3.08 to 3.15.</p>

<p>Storable no longer probes for recursion limits at build time. <a href="https://github.com/Perl/perl5/issues/16780">[GH #16780]</a> and others.</p>

<p>Metasploit exploit code was included to test for CVE-2015-1992 detection, this caused anti-virus detections on at least one AV suite. The exploit code has been removed and replaced with a simple functional test. <a href="https://github.com/Perl/perl5/issues/16778">[GH #16778]</a></p>

</li>
<li><p><a href="./Test::Simple.html">Test::Simple</a> has been upgraded from version 1.302133 to 1.302162.</p>

</li>
<li><p><a href="./Thread::Queue.html">Thread::Queue</a> has been upgraded from version 3.12 to 3.13.</p>

</li>
<li><p><a href="./threads::shared.html">threads::shared</a> has been upgraded from version 1.58 to 1.60.</p>

<p>Added support for extra tracing of locking, this requires a <code>-DDEBUGGING</code> and extra compilation flags.</p>

</li>
<li><p><a href="./Time::HiRes.html">Time::HiRes</a> has been upgraded from version 1.9759 to 1.9760.</p>

</li>
<li><p><a href="./Time::Local.html">Time::Local</a> has been upgraded from version 1.25 to 1.28.</p>

</li>
<li><p><a href="./Time::Piece.html">Time::Piece</a> has been upgraded from version 1.3204 to 1.33.</p>

</li>
<li><p><a href="./Unicode::Collate.html">Unicode::Collate</a> has been upgraded from version 1.25 to 1.27.</p>

</li>
<li><p><a href="./Unicode::UCD.html">Unicode::UCD</a> has been upgraded from version 0.70 to 0.72.</p>

</li>
<li><p><a href="./User::grent.html">User::grent</a> has been upgraded from version 1.02 to 1.03.</p>

</li>
<li><p><a href="utf8.html">utf8</a> has been upgraded from version 1.21 to 1.22.</p>

</li>
<li><p><a href="vars.html">vars</a> has been upgraded from version 1.04 to 1.05.</p>

<p><code>vars.pm</code> no longer disables non-vars strict when checking if strict vars is enabled. <a href="https://github.com/Perl/perl5/issues/15851">[GH #15851]</a>.</p>

</li>
<li><p><a href="version.html">version</a> has been upgraded from version 0.9923 to 0.9924.</p>

</li>
<li><p><a href="warnings.html">warnings</a> has been upgraded from version 1.42 to 1.44.</p>

</li>
<li><p><a href="./XS::APItest.html">XS::APItest</a> has been upgraded from version 0.98 to 1.00.</p>

</li>
<li><p><a href="./XS::Typemap.html">XS::Typemap</a> has been upgraded from version 0.16 to 0.17.</p>

</li>
</ul>

<h2 id="Removed-Modules-and-Pragmata"><a class="permalink" href="perl5300delta.html#Removed-Modules-and-Pragmata">#</a><a id="Removed"></a>Removed Modules and Pragmata</h2>

<p>The following modules will be removed from the core distribution in a future release, and will at that time need to be installed from CPAN. Distributions on CPAN which require these modules will need to list them as prerequisites.</p>

<p>The core versions of these modules will now issue <code>&quot;deprecated&quot;</code>-category warnings to alert you to this fact. To silence these deprecation warnings, install the modules in question from CPAN.</p>

<p>Note that these are (with rare exceptions) fine modules that you are encouraged to continue to use. Their disinclusion from core primarily hinges on their necessity to bootstrapping a fully functional, CPAN-capable Perl installation, not usually on concerns over their design.</p>

<ul>

<li><p>B::Debug is no longer distributed with the core distribution. It continues to be available on CPAN as <code><a href="./B::Debug.html">B::Debug</a></code>.</p>

</li>
<li><p>Locale::Codes has been removed at the request of its author. It continues to be available on CPAN as <code><a href="./Locale::Codes.html">Locale::Codes</a></code> <a href="https://github.com/Perl/perl5/issues/16660">[GH #16660]</a>.</p>

</li>
</ul>

<h1 id="Documentation"><a class="permalink" href="perl5300delta.html#Documentation">#</a>Documentation</h1>

<h2 id="Changes-to-Existing-Documentation"><a class="permalink" href="perl5300delta.html#Changes-to-Existing-Documentation">#</a><a id="Changes"></a>Changes to Existing Documentation</h2>

<p>We have attempted to update the documentation to reflect the changes listed in this document. If you find any we have missed, send email to <a href="mailto:perlbug@perl.org">perlbug@perl.org</a>.</p>

<h3 id="perlapi"><a class="permalink" href="perl5300delta.html#perlapi">#</a><a href="perlapi.html">perlapi</a></h3>

<ul>

<li><p><code>AvFILL()</code> was wrongly listed as deprecated. This has been corrected. <a href="https://github.com/Perl/perl5/issues/16586">[GH #16586]</a></p>

</li>
</ul>

<h3 id="perlop"><a class="permalink" href="perl5300delta.html#perlop">#</a><a href="perlop.html">perlop</a></h3>

<ul>

<li><p>We no longer have null (empty line) here doc terminators, so <a href="perlop.html">perlop</a> should not refer to them.</p>

</li>
<li><p>The behaviour of <code>tr</code> when the delimiter is an apostrophe has been clarified. In particular, hyphens aren&#39;t special, and <code>\x{}</code> isn&#39;t interpolated. <a href="https://github.com/Perl/perl5/issues/15853">[GH #15853]</a></p>

</li>
</ul>

<h3 id="perlreapi,-perlvar"><a class="permalink" href="perl5300delta.html#perlreapi,-perlvar">#</a><a id="perlreapi"></a><a id="perlreapi-perlvar"></a><a href="perlreapi.html">perlreapi</a>, <a href="perlvar.html">perlvar</a></h3>

<ul>

<li><p>Improve docs for lastparen, lastcloseparen.</p>

</li>
</ul>

<h3 id="perlfunc"><a class="permalink" href="perl5300delta.html#perlfunc">#</a><a href="perlfunc.html">perlfunc</a></h3>

<ul>

<li><p>The entry for <a href="perlfunc.html#-X">&quot;-X&quot; in perlfunc</a> has been clarified to indicate that symbolic links are followed for most tests.</p>

</li>
<li><p>Clarification of behaviour of <code>reset EXPR</code>.</p>

</li>
<li><p>Try to clarify that <code>ref(qr/xx/)</code> returns <code>Regexp</code> rather than <code>REGEXP</code> and why. <a href="https://github.com/Perl/perl5/issues/16801">[GH #16801]</a>.</p>

</li>
</ul>

<h3 id="perlreref"><a class="permalink" href="perl5300delta.html#perlreref">#</a><a href="perlreref.html">perlreref</a></h3>

<ul>

<li><p>Clarification of the syntax of /(?(cond)yes)/.</p>

</li>
</ul>

<h3 id="perllocale"><a class="permalink" href="perl5300delta.html#perllocale">#</a><a href="perllocale.html">perllocale</a></h3>

<ul>

<li><p>There are actually two slightly different types of UTF-8 locales: one for Turkic languages and one for everything else. Starting in Perl v5.30, Perl seamlessly handles both types.</p>

</li>
</ul>

<h3 id="perlrecharclass"><a class="permalink" href="perl5300delta.html#perlrecharclass">#</a><a href="perlrecharclass.html">perlrecharclass</a></h3>

<ul>

<li><p>Added a note for the ::xdigit:: character class.</p>

</li>
</ul>

<h3 id="perlvar"><a class="permalink" href="perl5300delta.html#perlvar">#</a><a href="perlvar.html">perlvar</a></h3>

<ul>

<li><p>More specific documentation of paragraph mode. <a href="https://github.com/Perl/perl5/issues/16787">[GH #16787]</a>.</p>

</li>
</ul>

<h1 id="Diagnostics"><a class="permalink" href="perl5300delta.html#Diagnostics">#</a>Diagnostics</h1>

<p>The following additions or changes have been made to diagnostic output, including warnings and fatal error messages. For the complete list of diagnostic messages, see <a href="perldiag.html">perldiag</a>.</p>

<h2 id="Changes-to-Existing-Diagnostics"><a class="permalink" href="perl5300delta.html#Changes-to-Existing-Diagnostics">#</a><a id="Changes1"></a>Changes to Existing Diagnostics</h2>

<ul>

<li><p>As noted under <a href="perl5300delta.html#Incompatible-Changes">&quot;Incompatible Changes&quot;</a> above, the deprecation warning &quot;Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <span style="white-space: nowrap;">&lt;-- HERE</span> in m/%s/&quot; has been changed to the non-deprecation warning &quot;Unescaped left brace in regex is passed through in regex; marked by <span style="white-space: nowrap;">&lt;-- HERE</span> in m/%s/&quot;.</p>

</li>
<li><p>Specifying <code>\o{}</code> without anything between the braces now yields the fatal error message &quot;Empty \o{}&quot;. Previously it was &quot;Number with no digits&quot;. This means the same wording is used for this kind of error as with similar constructs such as <code>\p{}</code>.</p>

</li>
<li><p>Within the scope of the experimental feature <code>use re &#39;strict&#39;</code>, specifying <code>\x{}</code> without anything between the braces now yields the fatal error message &quot;Empty \x{}&quot;. Previously it was &quot;Number with no digits&quot;. This means the same wording is used for this kind of error as with similar constructs such as <code>\p{}</code>. It is legal, though not wise to have an empty <code>\x</code> outside of <code>re &#39;strict&#39;</code>; it silently generates a NUL character.</p>

</li>
<li><p><a href="perldiag.html#Type-of-arg-%25d-to-%25s-must-be-%25s-%28not-%25s%29">Type of arg %d to %s must be %s (not %s)</a></p>

<p>Attempts to push, pop, etc on a hash or glob now produce this message rather than complaining that they no longer work on scalars. <a href="https://github.com/Perl/perl5/issues/15774">[GH #15774]</a>.</p>

</li>
<li><p><a href="perldiag.html#Prototype-not-terminated">Prototype not terminated</a></p>

<p>The file and line number is now reported for this error. <a href="https://github.com/Perl/perl5/issues/16697">[GH #16697]</a></p>

</li>
<li><p>Under <code>-Dr</code> (or <code>use re &#39;Debug&#39;</code>) the compiled regex engine program is displayed. It used to use two different spellings for <i>infinity</i>, <code>INFINITY</code>, and <code>INFTY</code>. It now uses the latter exclusively, as that spelling has been around the longest.</p>

</li>
</ul>

<h1 id="Utility-Changes"><a class="permalink" href="perl5300delta.html#Utility-Changes">#</a><a id="Utility"></a>Utility Changes</h1>

<h2 id="xsubpp"><a class="permalink" href="perl5300delta.html#xsubpp">#</a><a href="xsubpp.html">xsubpp</a></h2>

<ul>

<li><p>The generated prototype (with <code>PROTOTYPES: ENABLE</code>) would include <code>OUTLIST</code> parameters, but these aren&#39;t arguments to the perl function. This has been rectified. <a href="https://github.com/Perl/perl5/issues/16746">[GH #16746]</a>.</p>

</li>
</ul>

<h1 id="Configuration-and-Compilation"><a class="permalink" href="perl5300delta.html#Configuration-and-Compilation">#</a><a id="Configuration"></a>Configuration and Compilation</h1>

<ul>

<li><p>Normally the thread-safe locale functions are used only on threaded builds. It is now possible to force their use on unthreaded builds on systems that have them available, by including the <code>-Accflags=&#39;-DUSE_THREAD_SAFE_LOCALE&#39;</code> option to <i>Configure</i>.</p>

</li>
<li><p>Improve detection of memrchr, strlcat, and strlcpy</p>

</li>
<li><p>Improve Configure detection of memmem(). <a href="https://github.com/Perl/perl5/issues/16807">[GH #16807]</a>.</p>

</li>
<li><p>Multiple improvements and fixes for -DPERL_GLOBAL_STRUCT build option.</p>

</li>
<li><p>Fix -DPERL_GLOBAL_STRUCT_PRIVATE build option.</p>

</li>
</ul>

<h1 id="Testing"><a class="permalink" href="perl5300delta.html#Testing">#</a>Testing</h1>

<ul>

<li><p><i>t/lib/croak/op</i> <a href="https://github.com/Perl/perl5/issues/15774">[GH #15774]</a>.</p>

<p>separate error for <code>push</code>, etc. on hash/glob.</p>

</li>
<li><p><i>t/op/svleak.t</i> <a href="https://github.com/Perl/perl5/issues/16749">[GH #16749]</a>.</p>

<p>Add test for <code>goto &amp;sub</code> in overload leaking.</p>

</li>
<li><p>Split <i>t/re/fold_grind.t</i> into multiple test files.</p>

</li>
<li><p>Fix intermittent tests which failed due to race conditions which surface during parallel testing. <a href="https://github.com/Perl/perl5/issues/16795">[GH #16795]</a>.</p>

</li>
<li><p>Thoroughly test paragraph mode, using a new test file, <i>t/io/paragraph_mode.t</i>. <a href="https://github.com/Perl/perl5/issues/16787">[GH #16787]</a>.</p>

</li>
<li><p>Some tests in <i>t/io/eintr.t</i> caused the process to hang on pre-16 Darwin. These tests are skipped for those version of Darwin.</p>

</li>
</ul>

<h1 id="Platform-Support"><a class="permalink" href="perl5300delta.html#Platform-Support">#</a><a id="Platform"></a>Platform Support</h1>

<h2 id="Platform-Specific-Notes"><a class="permalink" href="perl5300delta.html#Platform-Specific-Notes">#</a><a id="Platform1"></a>Platform-Specific Notes</h2>

<dl>

<dt id="HP-UX-11.11"><a class="permalink" href="perl5300delta.html#HP-UX-11.11">#</a><a id="HP"></a>HP-UX 11.11</dt>
<dd>

<p>An obscure problem in <code>pack()</code> when compiling with HP C-ANSI-C has been fixed by disabling optimizations in <i>pp_pack.c</i>.</p>

</dd>
<dt id="Mac-OS-X"><a class="permalink" href="perl5300delta.html#Mac-OS-X">#</a><a id="Mac"></a>Mac OS X</dt>
<dd>

<p>Perl&#39;s build and testing process on Mac OS X for <code>-Duseshrplib</code> builds is now compatible with Mac OS X System Integrity Protection (SIP).</p>

<p>SIP prevents binaries in <i>/bin</i> (and a few other places) being passed the <code>DYLD_LIBRARY_PATH</code> environment variable. For our purposes this prevents <code>DYLD_LIBRARY_PATH</code> from being passed to the shell, which prevents that variable being passed to the testing or build process, so running <code>perl</code> couldn&#39;t find <i>libperl.dylib</i>.</p>

<p>To work around that, the initial build of the <i>perl</i> executable expects to find <i>libperl.dylib</i> in the build directory, and the library path is then adjusted during installation to point to the installed library.</p>

<p><a href="https://github.com/Perl/perl5/issues/15057">[GH #15057]</a>.</p>

</dd>
<dt id="Minix3"><a class="permalink" href="perl5300delta.html#Minix3">#</a>Minix3</dt>
<dd>

<p>Some support for Minix3 has been re-added.</p>

</dd>
<dt id="Cygwin"><a class="permalink" href="perl5300delta.html#Cygwin">#</a>Cygwin</dt>
<dd>

<p>Cygwin doesn&#39;t make <code>cuserid</code> visible.</p>

</dd>
<dt id="Win32-Mingw"><a class="permalink" href="perl5300delta.html#Win32-Mingw">#</a><a id="Win32"></a>Win32 Mingw</dt>
<dd>

<p>C99 math functions are now available.</p>

</dd>
<dt id="Windows"><a class="permalink" href="perl5300delta.html#Windows">#</a>Windows</dt>
<dd>

<ul>

<li><p>The <code>USE_CPLUSPLUS</code> build option which has long been available in <i>win32/Makefile</i> (for <b>nmake</b>) and <i>win32/makefile.mk</i> (for <b>dmake</b>) is now also available in <i>win32/GNUmakefile</i> (for <b>gmake</b>).</p>

</li>
<li><p>The <b>nmake</b> makefile no longer defaults to Visual C++ 6.0 (a very old version which is unlikely to be widely used today). As a result, it is now a requirement to specify the <code>CCTYPE</code> since there is no obvious choice of which modern version to default to instead. Failure to specify <code>CCTYPE</code> will result in an error being output and the build will stop.</p>

<p>(The <b>dmake</b> and <b>gmake</b> makefiles will automatically detect which compiler is being used, so do not require <code>CCTYPE</code> to be set. This feature has not yet been added to the <b>nmake</b> makefile.)</p>

</li>
<li><p><code>sleep()</code> with warnings enabled for a <code>USE_IMP_SYS</code> build no longer warns about the sleep timeout being too large. <a href="https://github.com/Perl/perl5/issues/16631">[GH #16631]</a>.</p>

</li>
<li><p>Support for compiling perl on Windows using Microsoft Visual Studio 2019 (containing Visual C++ 14.2) has been added.</p>

</li>
<li><p>socket() now sets <code>$!</code> if the protocol, address family and socket type combination is not found. <a href="https://github.com/Perl/perl5/issues/16849">[GH #16849]</a>.</p>

</li>
<li><p>The Windows Server 2003 SP1 Platform SDK build, with its early x64 compiler and tools, was accidentally broken in Perl 5.27.9. This has now been fixed.</p>

</li>
</ul>

</dd>
</dl>

<h1 id="Internal-Changes"><a class="permalink" href="perl5300delta.html#Internal-Changes">#</a><a id="Internal"></a>Internal Changes</h1>

<ul>

<li><p>The sizing pass has been eliminated from the regular expression compiler. An extra pass may instead be needed in some cases to count the number of parenthetical capture groups.</p>

</li>
<li><p>A new function <a href="perlapi.html#my_strtod">&quot;<code>my_strtod</code>&quot; in perlapi</a> or its synonym, Strtod(), is now available with the same signature as the libc strtod(). It provides strotod() equivalent behavior on all platforms, using the best available precision, depending on platform capabilities and <i>Configure</i> options, while handling locale-related issues, such as if the radix character should be a dot or comma.</p>

</li>
<li><p>Added <code>newSVsv_nomg()</code> to copy a SV without processing get magic on the source. <a href="https://github.com/Perl/perl5/issues/16461">[GH #16461]</a>.</p>

</li>
<li><p>It is now forbidden to malloc more than <code>PTRDIFF_T_MAX</code> bytes. Much code (including C optimizers) assumes that all data structures will not be larger than this, so this catches such attempts before overflow happens.</p>

</li>
<li><p>Two new regnodes have been introduced <code>EXACT_ONLY8</code>, and <code>EXACTFU_ONLY8</code>. They&#39;re equivalent to <code>EXACT</code> and <code>EXACTFU</code>, except that they contain a code point which requires UTF-8 to represent/match. Hence, if the target string isn&#39;t UTF-8, we know it can&#39;t possibly match, without needing to try.</p>

</li>
<li><p><code>print_bytes_for_locale()</code> is now defined if <code>DEBUGGING</code>, Prior, it didn&#39;t get defined unless <code>LC_COLLATE</code> was defined on the platform.</p>

</li>
</ul>

<h1 id="Selected-Bug-Fixes"><a class="permalink" href="perl5300delta.html#Selected-Bug-Fixes">#</a><a id="Selected"></a>Selected Bug Fixes</h1>

<ul>

<li><p>Compilation under <code>-DPERL_MEM_LOG</code> and <code>-DNO_LOCALE</code> have been fixed.</p>

</li>
<li><p>Perl 5.28 introduced an <code>index()</code> optimization when comparing to -1 (or indirectly, e.g. &gt;= 0). When this optimization was triggered inside a <code>when</code> clause it caused a warning (&quot;Argument %s isn&#39;t numeric in smart match&quot;). This has now been fixed. <a href="https://github.com/Perl/perl5/issues/16626">[GH #16626]</a></p>

</li>
<li><p>The new in-place editing code no longer leaks directory handles. <a href="https://github.com/Perl/perl5/issues/16602">[GH #16602]</a>.</p>

</li>
<li><p>Warnings produced from constant folding operations on overloaded values no longer produce spurious &quot;Use of uninitialized value&quot; warnings. <a href="https://github.com/Perl/perl5/issues/16349">[GH #16349]</a>.</p>

</li>
<li><p>Fix for &quot;mutator not seen in (lex = ...) .= ...&quot; <a href="https://github.com/Perl/perl5/issues/16655">[GH #16655]</a>.</p>

</li>
<li><p><code>pack &quot;u&quot;, &quot;invalid uuencoding&quot;</code> now properly NUL terminates the zero-length SV produced. <a href="https://github.com/Perl/perl5/issues/16343">[GH #16343]</a>.</p>

</li>
<li><p>Improve the debugging output for calloc() calls with <code>-Dm</code>. <a href="https://github.com/Perl/perl5/issues/16653">[GH #16653]</a>.</p>

</li>
<li><p>Regexp script runs were failing to permit ASCII digits in some cases. <a href="https://github.com/Perl/perl5/issues/16704">[GH #16704]</a>.</p>

</li>
<li><p>On Unix-like systems supporting a platform-specific technique for determining <a href="perlvar.html#%24%5EX"><code>$^X</code></a>, Perl failed to fall back to the generic technique when the platform-specific one fails (for example, a Linux system with /proc not mounted). This was a regression in Perl 5.28.0. <a href="https://github.com/Perl/perl5/issues/16715">[GH #16715]</a>.</p>

</li>
<li><p><a href="SDBM_File.html">SDBM_File</a> is now more robust with corrupt database files. The improvements do not make SDBM files suitable as an interchange format. <a href="https://github.com/Perl/perl5/issues/16164">[GH #16164]</a>.</p>

</li>
<li><p><code>binmode($fh);</code> or <code>binmode($fh, &#39;:raw&#39;);</code> now properly removes the <code>:utf8</code> flag from the default <code>:crlf</code> I/O layer on Win32. <a href="https://github.com/Perl/perl5/issues/16730">[GH #16730]</a>.</p>

</li>
<li><p>The experimental reference aliasing feature was misinterpreting array and hash slice assignment as being localised, e.g.</p>

<pre><code>\(@a[3,5,7]) = \(....);</code></pre>

<p>was being interpreted as:</p>

<pre><code>local \(@a[3,5,7]) = \(....);</code></pre>

<p><a href="https://github.com/Perl/perl5/issues/16701">[GH #16701]</a>.</p>

</li>
<li><p><code>sort SUBNAME</code> within an <code>eval EXPR</code> when <code>EXPR</code> was UTF-8 upgraded could panic if the <code>SUBNAME</code> was non-ASCII. <a href="https://github.com/Perl/perl5/issues/16979">[GH #16979]</a>.</p>

</li>
<li><p>Correctly handle realloc() modifying <code>errno</code> on success so that the modification isn&#39;t visible to the perl user, since realloc() is called implicitly by the interpreter. This modification is permitted by the C standard, but has only been observed on FreeBSD 13.0-CURRENT. <a href="https://github.com/Perl/perl5/issues/16907">[GH #16907]</a>.</p>

</li>
<li><p>Perl now exposes POSIX <code>getcwd</code> as <code>Internals::getcwd()</code> if available. This is intended for use by <code>Cwd.pm</code> during bootstrapping and may be removed or changed without notice. This fixes some bootstrapping issues while building perl in a directory where some ancestor directory isn&#39;t readable. <a href="https://github.com/Perl/perl5/issues/16903">[GH #16903]</a>.</p>

</li>
<li><p><code>pack()</code> no longer can return malformed UTF-8. It croaks if it would otherwise return a UTF-8 string that contains malformed UTF-8. This protects against potential security threats. <a href="https://github.com/Perl/perl5/issues/16035">[GH #16035]</a>.</p>

</li>
<li><p>See <a href="perl5300delta.html#Any-set-of-digits-in-the-Common-script-are-legal-in-a-script-run-of-another-script">&quot;Any set of digits in the Common script are legal in a script run of another script&quot;</a>.</p>

</li>
<li><p>Regular expression matching no longer leaves stale UTF-8 length magic when updating <code>$^R</code>. This could result in <code>length($^R)</code> returning an incorrect value.</p>

</li>
<li><p>Reduce recursion on ops <a href="https://github.com/Perl/perl5/issues/11866">[GH #11866]</a>.</p>

<p>This can prevent stack overflow when processing extremely deep op trees.</p>

</li>
<li><p>Avoid leak in multiconcat with overloading. <a href="https://github.com/Perl/perl5/issues/16823">[GH #16823]</a>.</p>

</li>
<li><p>The handling of user-defined <code>\p{}</code> properties (see <a href="perlunicode.html#User-Defined-Character-Properties">&quot;User-Defined Character Properties&quot; in perlunicode</a>) has been rewritten to be in C (instead of Perl). This speeds things up, but in the process several inconsistencies and bug fixes are made.</p>

<ol>

<li><p>A few error messages have minor wording changes. This is essentially because the new way is integrated into the regex error handling mechanism that marks the position in the input at which the error occurred. That was not possible previously. The messages now also contain additional back-trace-like information in case the error occurs deep in nested calls.</p>

</li>
<li><p>A user-defined property is implemented as a perl subroutine with certain highly constrained naming conventions. It was documented previously that the sub would be in the current package if the package was unspecified. This turned out not to be true in all cases, but now it is.</p>

</li>
<li><p>All recursive calls are treated as infinite recursion. Previously they would cause the interpreter to panic. Now, they cause the regex pattern to fail to compile.</p>

</li>
<li><p>Similarly, any other error likely would lead to a panic; now to just the pattern failing to compile.</p>

</li>
<li><p>The old mechanism did not detect illegal ranges in the definition of the property. Now, the range max must not be smaller than the range min. Otherwise, the pattern fails to compile.</p>

</li>
<li><p>The intention was to have each sub called only once during the lifetime of the program, so that a property&#39;s definition is immutable. This was relaxed so that it could be called once for all /i compilations, and potentially a second time for non-/i (the sub is passed a parameter indicating which). However, in practice there were instances when this was broken, and multiple calls were possible. Those have been fixed. Now (besides the /i,non-/i cases) the only way a sub can be called multiple times is if some component of it has not been defined yet. For example, suppose we have sub IsA() whose definition is known at compile time, and it in turn calls isB() whose definition is not yet known. isA() will be called each time a pattern it appears in is compiled. If isA() also calls isC() and that definition is known, isC() will be called just once.</p>

</li>
<li><p>There were some races and very long hangs should one thread be compiling the same property as another simultaneously. These have now been fixed.</p>

</li>
</ol>

</li>
<li><p>Fixed a failure to match properly.</p>

<p>An EXACTFish regnode has a finite length it can hold for the string being matched. If that length is exceeded, a second node is used for the next segment of the string, for as many regnodes as are needed. Care has to be taken where to break the string, in order to deal multi-character folds in Unicode correctly. If we want to break a string at a place which could potentially be in the middle of a multi-character fold, we back off one (or more) characters, leaving a shorter EXACTFish regnode. This backing off mechanism contained an off-by-one error. <a href="https://github.com/Perl/perl5/issues/16806">[GH #16806]</a>.</p>

</li>
<li><p>A bare <code>eof</code> call with no previous file handle now returns true. <a href="https://github.com/Perl/perl5/issues/16786">[GH #16786]</a></p>

</li>
<li><p>Failing to compile a format now aborts compilation. Like other errors in sub-parses this could leave the parser in a strange state, possibly crashing perl if compilation continued. <a href="https://github.com/Perl/perl5/issues/16169">[GH #16169]</a></p>

</li>
<li><p>If an in-place edit is still in progress during global destruction and the process exit code (as stored in <code>$?</code>) is zero, perl will now treat the in-place edit as successful, replacing the input file with any output produced.</p>

<p>This allows code like:</p>

<pre><code class="plaintext">perl -i -ne &#39;print &quot;Foo&quot;; last&#39;</code></pre>

<p>to replace the input file, while code like:</p>

<pre><code class="plaintext">perl -i -ne &#39;print &quot;Foo&quot;; die&#39;</code></pre>

<p>will not. Partly resolves <a href="https://github.com/Perl/perl5/issues/16748">[GH #16748]</a>.</p>

</li>
<li><p>A regression in 5.28 caused the following code to fail</p>

<pre><code class="plaintext">close(STDIN); open(CHILD, &quot;|wc -l&quot;)&#39;</code></pre>

<p>because the child&#39;s stdin would be closed on exec. This has now been fixed.</p>

</li>
<li><p>Fixed an issue where compiling a regexp containing both compile-time and run-time code blocks could lead to trying to compile something which is invalid syntax.</p>

</li>
<li><p>Fixed build failures with <code>-DNO_LOCALE_NUMERIC</code> and <code>-DNO_LOCALE_COLLATE</code>. <a href="https://github.com/Perl/perl5/issues/16771">[GH #16771]</a>.</p>

</li>
<li><p>Prevent the tests in <i>ext/B/t/strict.t</i> from being skipped. <a href="https://github.com/Perl/perl5/issues/16783">[GH #16783]</a>.</p>

</li>
<li><p><code>/di</code> nodes ending or beginning in <i>s</i> are now <code>EXACTF</code>. We do not want two <code>EXACTFU</code> to be joined together during optimization, and to form a <code>ss</code>, <code>sS</code>, <code>Ss</code> or <code>SS</code> sequence; they are the only multi-character sequences which may match differently under <code>/ui</code> and <code>/di</code>.</p>

</li>
</ul>

<h1 id="Acknowledgements"><a class="permalink" href="perl5300delta.html#Acknowledgements">#</a>Acknowledgements</h1>

<p>Perl 5.30.0 represents approximately 11 months of development since Perl 5.28.0 and contains approximately 620,000 lines of changes across 1,300 files from 58 authors.</p>

<p>Excluding auto-generated files, documentation and release tools, there were approximately 510,000 lines of changes to 750 .pm, .t, .c and .h files.</p>

<p>Perl continues to flourish into its fourth decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.30.0:</p>

<p>Aaron Crane, Abigail, Alberto Simões, Alexandr Savca, Andreas König, Andy Dougherty, Aristotle Pagaltzis, Brian Greenfield, Chad Granum, Chris &#39;BinGOs&#39; Williams, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan Book, Dan Dedrick, Daniel Dragan, Dan Kogai, David Cantrell, David Mitchell, Dominic Hargreaves, E. Choroba, Ed J, Eugen Konkov, François Perrad, Graham Knop, Hauke D, H.Merijn Brand, Hugo van der Sanden, Jakub Wilk, James Clarke, James E Keenan, Jerry D. Hedden, Jim Cromie, John SJ Anderson, Karen Etheridge, Karl Williamson, Leon Timmermans, Matthias Bethke, Nicholas Clark, Nicolas R., Niko Tyni, Pali, Petr Písař, Phil Pearl (Lobbes), Richard Leach, Ryan Voots, Sawyer X, Shlomi Fish, Sisyphus, Slaven Rezic, Steve Hay, Sullivan Beck, Tina Müller, Tomasz Konojacki, Tom Wyant, Tony Cook, Unicode Consortium, Yves Orton, Zak B. Elep.</p>

<p>The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of most of the (very much appreciated) contributors who reported issues to the Perl bug tracker. Noteworthy in this release were the large number of bug fixes made possible by Sergey Aleynikov&#39;s high quality perlbug reports for issues he discovered by fuzzing with AFL.</p>

<p>Many of the changes included in this version originated in the CPAN modules included in Perl&#39;s core. We&#39;re grateful to the entire CPAN community for helping Perl to flourish.</p>

<p>For a more complete list of all of Perl&#39;s historical contributors, please see the <i>AUTHORS</i> file in the Perl source distribution.</p>

<h1 id="Reporting-Bugs"><a class="permalink" href="perl5300delta.html#Reporting-Bugs">#</a><a id="Reporting"></a>Reporting Bugs</h1>

<p>If you find what you think is a bug, you might check the perl bug database at <a href="https://rt.perl.org/">https://rt.perl.org/</a>. There may also be information at <a href="http://www.perl.org/">http://www.perl.org/</a>, the Perl Home Page.</p>

<p>If you believe you have an unreported bug, please run the <a href="perlbug.html">perlbug</a> program included with your release. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report, along with the output of <code>perl -V</code>, will be sent off to perlbug@perl.org to be analysed by the Perl porting team.</p>

<p>If the bug you are reporting has security implications which make it inappropriate to send to a publicly archived mailing list, then see <a href="perlsec.html#SECURITY-VULNERABILITY-CONTACT-INFORMATION">&quot;SECURITY VULNERABILITY CONTACT INFORMATION&quot; in perlsec</a> for details of how to report the issue.</p>

<h1 id="Give-Thanks"><a class="permalink" href="perl5300delta.html#Give-Thanks">#</a><a id="Give"></a>Give Thanks</h1>

<p>If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so by running the <code>perlthanks</code> program:</p>

<pre><code class="plaintext">perlthanks</code></pre>

<p>This will send an email to the Perl 5 Porters list with your show of thanks.</p>

<h1 id="SEE-ALSO"><a class="permalink" href="perl5300delta.html#SEE-ALSO">#</a><a id="SEE"></a>SEE ALSO</h1>

<p>The <i>Changes</i> file for an explanation of how to view exhaustive details on what changed.</p>

<p>The <i>INSTALL</i> file for how to build Perl.</p>

<p>The <i>README</i> file for general stuff.</p>

<p>The <i>Artistic</i> and <i>Copying</i> files for copyright information.</p>


      </div>
      <div id="footer">
        <p>Perldoc Browser is maintained by Dan Book (<a href="https://metacpan.org/author/DBOOK">DBOOK</a>). Please contact him via the <a href="https://github.com/Grinnz/perldoc-browser/issues">GitHub issue tracker</a> or <a href="mailto:dbook@cpan.org">email</a> regarding any issues with the site itself, search, or rendering of documentation.</p>

<p>The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. Please contact them via the <a href="https://github.com/Perl/perl5/issues">Perl issue tracker</a>, the <a href="https://lists.perl.org/list/perl5-porters.html">mailing list</a>, or <a href="https://kiwiirc.com/client/irc.perl.org/p5p">IRC</a> to report any issues with the contents or format of the documentation.</p>


      </div>
    </div>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.slim.min.js" integrity="sha512-/DXTXr6nQodMUiq+IUJYCt2PPOUjrHJ9wFrqpJ3XkgPNOZVfMok7cRw6CSxyCQxXn6ozlESsSh1/sMCTF1rL/g==" crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.1/umd/popper.min.js" integrity="sha512-ubuT8Z88WxezgSqf3RLuNi5lmjstiJcyezx34yIU2gAHonIi27Na7atqzUZCOoY4CExaoFumzOsFQ2Ch+I/HCw==" crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script>
    <script src="../highlight.pack.js"></script>
    <script>hljs.highlightAll();</script>
  </body>
</html>
